Protect Your Equipment ...

If you are testing OIL Furnaces, You need to pull a smoke test first...

You know moisture is your sensors' worst enemy ~ but heavy soot environments can clog, over-range and even damage sensors, as well as other integral parts of your analyzer. If you are testing oil, make it a habit to smoke test FIRST! If you are not pulling a 1 or less, DO NOT use your analyzer until you've corrected the problem!